The present invention relates in general to automotive crash detection, and, more specifically, to detecting the occurrence of a light to moderate impact event having a severity less than one that should trigger deployment of a passive restraint such as an air bag.
Vehicle crash detection is a well-developed technology in the context of passive restraint systems which deploy during a crash in order to protect the vehicle occupants. Specialized sensors and robust detection algorithms provide a high reliability in detecting the onset of a crash that has a sufficient severity to automatically activate a passive restraint.
A typical crash sensing system may be comprised of an array of accelerometers, for example. Longitudinal and lateral acceleration sensor signals from the accelerometers can be generated within or communicated to a Restraints Control Module (RCM) which makes a deployment decision. Accelerometers mounted in the RCM have detection ranges from about −50 g to about +50 g. Satellite accelerometers remotely located in the front and sides of the vehicle typically have ranges from about −250 g tom about +250 g. Light to moderate impacts involving lower levels of acceleration cannot be reliably detected using the existing accelerometers. However, there would be benefits to having an ability to detect light impacts, i.e., when the impact severity is less than what the RCM module uses to initiate a restraint deployment.
Although light impacts between vehicles do not cause significant damage to the driver or passenger directly, they could begin a chain of post impact events which can lead to undesired outcomes such as further impacts or rollovers. Therefore, the detection and recording of occurrences of light impact collisions may of interest to vehicle owners, vehicle fleet operators, law-enforcement personnel, and insurance providers. This invention discloses techniques and systems for detecting light impacts to enable many different kinds of reactions such as modified vehicle control, the real-time alerting of third parties (e.g., insurance, fleet, and law enforcement agencies), and the recording/storage of incident information in the vehicle for later use by fleet operators and law enforcement for accident reconstruction.
Known methods for detecting impacts in restraint systems may not be apt for detecting light impacts because they typically require different sensors that may not be well suited to detection of light crashes and they may require significant computing resources and/or data transmission. A typical automotive electronics architecture comprises a plurality of distributed controller modules and sensor devices connected as nodes in a multiplex communication network. In view of the ultimate uses to which the detection of a light impact would be put, an optimal implementation would typically locate the light-impact detection function in a controller module other than a restraints control module (e.g., in a body control module or a powertrain control module) where computing resources may be in short supply. Therefore, it would be desirable to achieve reliable detection of light impact events using low computing overhead while consuming a minimal amount of data traffic over a multiplex controller network.